More cleanups in the parser.

jedi/evaluate/docstrings.py

@@ -191,7 +191,7 @@ def follow_param(module_context, param):
             [p for param_str in _search_param_in_docstr(docstring, str(param.name))
                 for p in _evaluate_for_statement_string(module_context, param_str)]
         )
-    func = param.parent_function
+    func = param.get_parent_function()
     types = eval_docstring(func.raw_doc)
     if func.name.value == '__init__':
         cls = search_ancestor(func, 'classdef')

jedi/evaluate/finder.py

@@ -98,7 +98,7 @@ class NameFinder(object):
         if self._context.predefined_names:
             # TODO is this ok? node might not always be a tree.Name
             node = self._name
-            while node is not None and not isinstance(node, tree.IsScope):
+            while node is not None and not node.is_scope():
                 node = node.parent
                 if node.type in ("if_stmt", "for_stmt", "comp_for"):
                     try: